Document EP 2407037 A1 describes stackable trays provided with an apertured support surface on which slices of a meat product are arranged mutually adjacent to but not overlapping one another, in a single layer. These trays loaded with the slices are conveyed by a conveyor device along a path including one or more translation sections inside a hermetic processing chamber where modified atmospheric conditions have been created for drying and curing the slices. Nevertheless, this document proposes a complicated system of gates for introducing the trays in and extracting the trays from the hermetic processing chamber, making it rather unfeasible economically speaking.
Document GB 1402652 discloses a treatment unit for treating foodstuffs by means of steam, where said foodstuffs are arranged in trays, and said trays are conveyed vertically by means of a conveyor device made up of a pair of roller chains located on the sides of the vertical translation section. Said roller chains have L-shaped side projections on which said trays are supported.
A drawback of said invention described in document GB 1402652 is that it only allows one vertical tray translation section, thus forcing said treatment unit to have a lower inlet and an upper outlet and a limited travel. Furthermore, the roller chains forming the conveyor device engage in toothed pulleys that rotate about axes parallel to the tray loading and unloading direction, which would make it impossible for one and the same roller chain to convey the trays upwards and downwards in the same time in a hypothetical embodiment with two vertical translation sections.
Document EP 2213178 A1 discloses a forced convection treatment unit for a meat product cut into slices, where a plurality of trays loaded with the slices of the meat product are conveyed by means of a conveyor device along a path inside an enclosure while gaseous fluid circulation means create two treatment gaseous fluid streams inside the enclosure in two opposite directions which are transverse to the forward direction of the trays, such that the trays receive one of the treatment gaseous fluid streams from a first side along a first section of said path and the other one of the treatment gaseous fluid streams from a second opposite side along a second section of the path.
A drawback of the forced convection treatment unit of the mentioned document EP 2213178 A1 is that it is difficult to be adapted to enclosures with paths of different lengths since such adaptation would involve completely modifying the dimensions of the treatment gaseous fluid inlets, outlets and conduits associated with the enclosure.
In one embodiment, document EP 2213178 A1 proposes linking two or more of such treatment units, each provided with its own enclosure, its own internal conveyor device and its own gaseous fluid circulation means by means of one or more external conveyor sections for conveying the trays from one enclosure to another in order to elongate the path along which the trays loaded with slices are subjected to the effect of the forced convection of treatment gaseous fluid. Nevertheless, this solution is costly due to the multiplicity of elements.